People aren't simply thinking machines. You can't just feed them data and expect them to do the logical thing. You have to craft your message in a way that appeals to them emotionally, not just logically. I don't think it's cynical to say that. It's just the way things are. Advertisers, politicians, and other scam artists are using it on us every day. We have to study this so that we can A) recognize when it's being used on us and B) learn how to use it ourselves.
Your A seems more reasonable to me than the B side.
For example, we are quick to cite logical fallacies on this forum as a short-cut way of pointing out a type of false logical manipulation. We do it to point out when a poster is being disingenuous, or outright fraudulent, or even merely to show the logic is poor. We would do the same for an emotionally laden appeal when that emotion is false as well.
Dishonesty isn't merely a technique, on par with good diction and logical flow - it's an attempt to abuse mechanisms in place we use to ferret out the truth, a way to misdirect and mislead.
But there's a much, much bigger problem I have with this line of reasoning. You can recast any human interaction as manipulation.
If I do something nice for my wife, is it because I selflessly love her? Or am I doing it to manipulate her into returning my affections? This mutual manipulation is what good relationships are made of. In fact, if the opposite were true, i.e. I did nice things for my wife and she did not reciprocate, it wouldn't be a healthy relationship. The "ideal" love, that which is never tarnished no matter how badly the other person treats you, is not healthy. That's what abusive relationships are made of.
Again, I disagree. Manipulation implies an asymmetry of power or information. I can modify your behavior by altering my own, so long as you cannot detect the trick. On the opposite hand, we have the "speaking truth to power" which works by recruiting an outside element - the true situation - to overcome the false narrative the more powerful would put in play.
I also find it an odd description of a healthy relationship which is dependent on maintaining some fictional element of importance. Feigning more interest than you actually feel about home decor to appease your wife is not on par with pretending faithfulness and love while you secretly plan your extended hike on the Appalachian Trail.
"Some dishonesty is unavoidable" does not open the door to "any lie I can get you to believe is fine," no more than a claim that I am mortal means my murder shouldn't be of concern, since we are all worm food eventually.
But, hey! Never mind all that. I'm attempting to manipulate you right now by trying to make a persuasive argument.
And I assume you are doing so honestly and visibly, without a hidden agenda. Otherwise, the post would fall under "Poe" or "trolling."
I try to manipulate people into being happy by smiling at them. If I give a dollar to a homeless person, I'm trying to manipulate them into having a better day. Also, of course, parents manipulate their children to get good grades, and bosses try, in various ways, to manipulate their employees to work harder and more efficiently. And so on and so on.
In questions of morality intentions matter. To the extent those behaviors are underhanded, they are tainted. I can cut to kill or cut to cure. Both are cuts.
The only time manipulation gets called out on the carpet is A) when it's used for some nefarious purpose or B) people are trying to study it and become better at it. Not only is manipulation not inherently bad, but human interaction itself would be impossible without it.
I think you are overloading the word to mean a generalized human interaction - something I don't think is supported. The word more properly means pretty much what we find in the dictionary: handle or control (a tool, mechanism, etc.), typically in a skillful manner; and control or influence (a person or situation) cleverly, unfairly, or unscrupulously.
Either definition implies power over another (as a tool or as a victim). This is the part which I find repugnant. Convincing someone by logical argument is not then manipulation, although I grant that persuasion may have elements of it, and commonly does in modern life. But the ubiquity doesn't add status, rather, it makes the topic more depressing in a mutually assured destruction way.
Even if I drop the moral outrage, the techniques still come up short, for they require more energy and attention (even training), and hence take more resources. Dishonesty is less efficient. For every winner in the liar's game, there is a loser, and truth-pollution adds to the carrying cost of relationships.
There's one final, real-world problem as well. Suppose it is to my advantage to be completely truthful and open about some particular topic - say, for example, I really do intend to pay that $1,000 back should you lend it to me. There is no readily available mechanism for you to detect my sincerity in a landscape I have already populated with pleasant fictions. Manipulation is a road that is very difficult to travel backwards on. Once you know I will make false presentments to gain an advantage, you should always be suspicious of me. I have lost the power of truth by the very mechanism of trying to falsely mimic it.
One interesting consequence of this is how surprising we find it when there is no zinger in the fine print, when the picture on the box accurately portrays the contents, or when the darn thing really is free.